Ring-c unsaturated alpha-substituted side-chain steroid ketones and process



Patented Aug. 23, 1949 RING-C UNSATURATED ALPHA- SUBSTI- TUTED SIDE-CHAIN STEROID KETONES AND PROCESS Tadeus Reichstein, Basel, Switzerland, assignor to Organon, Inc., Orange, N. Y.

No Drawing. Griginal application February 5,

1943, Serial No. 474,892.

Divided and this application February 27, 1946, Serial No. 650,734. In Switzerland October 5, 1942 7 Claims. 1

In U. S. Patent No. 2,245,299, a process is described for the manufacture of saturated and unsaturated derivatives of pregnane-3-ol-20-one which contain in the 2 -position a diazo group, halogen or a monovalent oxygen radical and which may be further substituted in the ring system, in particular with hydroxyl, acyloxy, alkoxy, or oxide groups. The process comprises converting into the corresponding acid halides, saturated or unsaturated derivatives of B-hydroxy-etiocholanic acid or derivatives of the same, which are further substituted in the ring system, and whose hydroxyl groups in the ring are protected by etherification or acylation; these acid halides are introduced into an excess of diazomethane solution and the 21-diazo ketones obtained subjected, if desired after preliminary alkaline saponification, to the action of aqueous inorganic acids containing oxygen or organic sulphonic acids, hydrohalic acids or organic carboxylic acids; or diazomethane is slowly added to the acid halides mentioned and the product obtained subjected, if desired, to acid saponification; in the case 2l-hydroxy ketones are obtained they may be subjected after etherification to alkaline saponification, and in the case of 21-halo-ketones, the halogen atoms may be replaced by monovalent radicals containing oxygen.

In French Patent No. 840,417 an analogous process is described, starting from carboxylic acid 5 halides which are derived from ring ketones of the cyclopentanopolyhydrophenanthrene series or their enol derivatives.

In none of these patents are mentioned as starting products carboxylic acids of the cyclopentanopolyhydrophenanthrene series or their halides which contain in ring A in the 3-position an esterified or etherified hydroxyl group, and in ring C in the 11- and/or 12-position, keto groups, esterified or etherified hydroxyl groups or a double bond in which the carbon atom 11 participates.

It has now been found that tit-Substituted side chain ketones of the cyclopentanopolyhydrophenanthrene series can also be obtained by starting from carboxylic acid halides of the said series which contain, in ring A in 3-positi-on a group convertible into hydroxyl by hydrolysis and, in ring 0 in 11- and/or 12-poslti0n, keto groups, groups convertible by hydrolysis into hydroxyl groups or a double bond in which the carbon atom 11 participates. These starting materials, which also may be further substituted, are caused to react with aliphatic diazo compounds; in the diazo-ketones or halo-ketones obtained the protected hydroxyl group in 3-positi0n is set free by means of, in particular, hydrolyzing agents,-and converted in known manner into a keto group, if necessary with temporary protection of carbon double bonds which may be present, and subsequently, or before oxidation of the free hydroxyl group, the diazo-ketone or halo-ketone grouping is converted into a free or esterified ketol group by means of organic or inorganic acids 01' alkalis or carboxylic acid salts; then a double bond is introduced, if desired, in the a-position to the 3- keto group in a known way and the product finally treated, if desired, with hydrolyzing and/or esterifying agents.

The starting materials may contain, in addition to those already mentioned, for example, the following substituents: substituted hydroxyl or carbinol groups, carbonyl or amino groups, halogen atoms, hydrocarbon residues, etc. They may be saturated, unsaturated'in one or more places and may be of any steric configuration. The following substances may, for example, be used as starting materials: halides of saturated or unsaturated, esterified or etherified, 3-hydroxy,3,7- or 3,17-dihydroxy, 3,7,17-trihydroxy, B-hydroxy-lketo etiocholanic acids or the corresponding cholanic, nor-cholanic or bis-nor-cholanic acids, which contain in' ring C in the 11- and/or 12- :position keto'groups, esterified or etherified hydroxyl groups, or a double bond in which the carbon atom 11 participates, i. e. located in the 9, 1- or 11, 12-position. The protected hydroxyl groups, for example, can be esterified with inorganic or organic acids such as carboxylic acids, sulphonic acids or hydrohalic acids, or etherified with alcohols such as triarylmethyl or benzyl alcohols, or with phenols 'or enolized or acetalized carbonyl compounds. Finally, instead of the starting products mentioned, their derivatives, e. g. enol derivatives or acetals of the compounds containing keto groups, may be used. The carboxylic acids used to start with, may be obtained for example by degradation, in stages or radically, orby conversion of bile acids, sterols, genins from cardiac glucosides, etc. or synthetically starting 3 from the corresponding ring ketones. The surprising observation was made that acid halides of 11 or 12-keto acids can be prepared without difficulty and with a much better yield than, for example, those of 3-keto acids.

Amongst the aliphatic diazo compounds used for the reactionwith the acid halides may be mentioned, for example, diazomethane and monosubstituted diazomethanes, such as diazoethane, diazobutane, diazopropylene, phenyldiazomethane and diazoacetophenone, and further diazgcars 3 boxylic acid derivatives such as diazo-acetic acidesters, -amides or -nitriles, etc.

The reaction of the carboxylic acid halides with the diazo compounds takes place, on the one hand, with elimination of hydrohalide and formation of diazoketones This is particularly the case'whendiazo compounds containing carbonyl groups, such ,as diazo fatty acid derivatives, are used and in general when an excess of diazo compoundis continually present. If, however, the aliphatic di azo compounds are only added gradually to the acid halides, halo-ketones -c O([1H.Hlg)

are produced which are also obtainable by subse quent action of a hydro-halide on the diazo ketones.

The application of the diazok'etones or haloketones obtained takes place in crude condition orafter their separation and purification. As-

next step the protected hydroxyl group in 3-posi-' tion is set free. For this purpose hydrolyzing agents are generally used; reducing agents may also be used, however, e. g. if benzylethers are present. groups in the molecule, e. g. ester groups in ring 0, these may remain unchanged on using mild hydrolyzing agents, suchias bicarbonates, or may be simultaneously saponified on stronger hydrolysis e. g. with alkali hydroxides. Halo-ketones are best hydrolyzed with acidic agents.

The free 3-hydroxyl group is. converted, in a manner itself known, into aketo group, e. g. with oxidizing agents such as chromic acid in glacial acetic acid or with dehydrogenating agents, e. g. heating with copper powder, action of metal alcoholates or phenolates in the presence of ketones, such as acetone or cyclohexanone. necessary, carbon double-bondsrwhich may be present, are temporarily protected e. g. byg'addition and later elimination of halogen or'hydrohalide. Other'free hydroxyl'groups, e. g. present in ring C, may be converted'at' the same timeas the 3-hydroxyl'group into keto groups; On the otherhand, with cautious dehydrogenation, e. g." using aluminium alcoholate or phenolate inthe presence of ketones, a number of'free nucleari hydroxyl groups maybe only partly converted in to keto groups, particularly this one in 3--position After, or even before, oxidation of the 3-hydroxyl group, the diazo-ketogrouping, which may be present, is converted into a free'or 'esterified ketol grouping by the action of anhydrousordiluted organic or inorganic acids e; g. acetic acid, propionic acid, butyric acids, vcrotonic acids,- palmitic acid, benzoic acid, phenyl-acetic acid,

sulphuric acids, methane-sulphonic acid, toluenesulphonic acid, hydrohalic acids, phosphoric acids or boric acid. Acylates, halides or sulphonic acid esters thus can be obtained for "example. If a halogen-ketone group'is-present liftstead of the diazo-ketone group, the former is converted, before or after the described oxidation, into a free or esterifi'ed'ketol group by'means' ofalkaline agents e. g. bicarbonates'or of car-' boxylic acid salts.

If a double bond is to beintroduced in the a-positionto the 3'-keto-group, this can be done in a known way, e. g. by halogenationand subse-- queiit elimination'of hydrohalide.

In a further step, ester group's which maybe present can be saponified with" hydrolyzing If there are other protected hydroxyl agents. The relative sensitivity of the a-hydroxy' ketone group to alkali should be taken into consideration, so that it is preferable to work with acids orvery weak alkalis; such as bicarbonates. 5 Finally esterifying agentscan beallowed to act. Radicals of the above mentioned acids, but also, for example, of polycarboxylic acids, such as phthalic or succinic acid, or of carbonic acid or its derivatives, thus may be introduced. If several hydroxyl groups are present, a complete or only 'a partial esterification, particularly in the 21-position, can be undertaken.

The most important stages of the reaction may beillustrated by the following formulas:

g IUCQOHM I .Q

R=grou-p, convertible into hydroxyl by hydrolysis. Rf este'rified hydroxyl group; X=l or 2 keto or substituted or free hydroxyl bond...

Halogen...

groups,- or 1 double The products of the present process arethera' peutically extremely valuable compounds or may Example 1 5 parts of etio-desoxycholic acid diacetate,

M. Pt. 202--204= C. are dissolved in 26.5 parts of pure thionyl chloride, the solution is allowed to stand for 30 minutes at 0 0., then for hours at room temperature and then evaporated to dryness in vacuo with exclusion of moisture. The crystalline residue is dissolved in 30 parts of dry benzene and added at about -15 C. to a solution of diazomethane in about 250 parts of dry ether (prepared from 16 parts of nitroso-methyl carbamide and dried by repeated distillation over solid potassium hydroxide). The mixture is allowed to stand, with exclusion of moisture, first for 2 hours at 0 C., then for 22 hours at room temperature. It is then concentrated considerably on a water-bath and finally completely dried in vacuo. The golden yellow, oily residue consists of 5.87 parts of crude 21-diazo pregnane- 3u,12p-diol-20-one-diacetate and is worked up directly.

For saponification of the two acetate groups, it is mixed with a solution of 3.37 parts potassium hydroxide (4.5 mol.) in 5 parts of water and '75 parts of methyl alcohol and allowed to stand for 22 hours at room temperature. A solution of about 6 parts of potassium bicarbonate in 120 parts of water is then added, the mixture freed from methyl alcohol in a vacuum and extracted with much ether. The ether solution is washed with water, dried over sodium sulphate and evaporated down. The product obtained consists of 4.39 parts :of a crude 21-diazo-pregnane- 30,12B-di01-20-01'19.

This preparation is heated in 25 parts of pure glacial acetic acid to 100 C. After 55 minutes the calculated quantity of gas is liberated and the reaction finished. The light brown solution is evaporated to dryness in vacuo, the residue dissolved in dry benzene and separated chromatographically by running through a column of aluminium oxide. After some oily material has been eluted, a compound is obtained with mixtures of ether and chloroform which gives on crystallisation from a mixture of ether and methyl alcohol, needles with a double melting point 94-110 C. and 144-148.5 C. When recrystallized from aqueous methyl alcohol it melts at 149.5-150.5 C. and has a specific rotation of [a] '-=+139.7i4 (in acetone). The product is pregnane-Zia,125,2l-triol-20-one-2l-monoacetate. With a mixture of chloroform, ethyl acetate and methyl alcohol a further amorphous product is extracted which contains the same monoacetate.

6 parts of the above mentioned compound are dissolved in 160 parts of pure glacial acetic acid, a solution of 3 parts of chromium trioxide in 160 parts of glacial acetic acid is added and the whole allowed to stand for 16 hours at 18 C. The mixture is evaporated down in vacuo at 0., a little water added to the residue and the latter extracted with plenty of ether. The ether solution is washed with dilute sulphuric acid, sodium carbonate solution and water, dried over sodium sulphate and evaporated down. Crystals are obtained from a mixture of benzene and ether, precipitation of which is completed by the addition of petroleum ether. They melt at 189-191 3 C. and have a specific rotation of (in acetone). The substance is pregnane2l-ol- 3,12,20-trione-acetate.

Considerable quantities of the same triketone can also be obtained by oxidation of the amorphous pregnane-3a,l2p,21-triol-20-one-2l-monoacetate.

The same triketone is further obtainable by oxidation with chromic acid of the pregnanc- 12p,21-diol-3,20-dione-2l-monoacetate, prepared as described in Example 2.

parts of pregnane-21-ol-3,l2,20-trione-acetatev are. dissolved in 950 parts of pure glacial acetic acid and a solution of bromine in glacial acetic acid, equivalent to 1 mol. bromine, is added. After an induction period of a few minutes, the solution rapidly becomes decolourized. It is then evaporated down in vacuo at 30 C. when transparent'crystals separate out which are washed with absolute ether and a mixture of ether and petroleum ether. The bromide obtained in this way melts at 182-187.5 C. The mother-liquors give, after evaporating down in vacuo, an amorphous substance which can be reduced to the initial parent product by heating with zinc dust and sodium acetate in glacial acetic acid.

The crystallized bromine compound is boiled with very pure pyridine for 5 hours under reflux. The mixture is then evaporated down in vacuo, the residue dissolved in ether, the ether solution washed with hydrochloric acid, sodium carbonate solution and water, dried and evaporated down. The residue is recrystallized from a mixture of acetone and ether and gives pale yellow pr sms which are dissolved in benzene and chromatographed by running through a column of aluminium oxide.

The fractions eluted with mixtures of benzene and petroleum ether and the first ones with benzene give a product which melts indefinitely at about -180 C. The further fractions extracted with absolute benzene, and mixtures of benzene and ether give, on recrystallization from a mixture of acetone and ether, the A -pregnene- 21-01-3,12,20-trione-monoacetate as colourless prisms of melting point 182-184 C. and specific rotation [a] =+228.6i3 (in acetone).

6 parts of this preparation are dissolved in 65 parts of methyl alcohol, a solution of '7 parts of potassium bicarbonate in 22 parts of water is added, and the whole allowed to stand for 23 hours at room temperature. A little water is then added and the methyl alcohol completely removed in vacuo. The material which separates out in crystalline form is filtered off with sue tion, washed with water and dried in vacuo. By extracting the aqueous fractions with a mixture of ether and chloroform (5:1) a small supplementary amount can be obtained. Double recrystallization from a mixture of benzene and ether gives colourless long needles which melt at ISO-183 C. and have a specific rotation of [a] =+238.9i3; [a] 54(;l=+293i3 (in dioxane).

The M-pregnene-21-ol3,12,20-trione obtained in this way can be converted in known manner intoany other ester e. g. the propionate, buvtyrates, succinate, tosylate or dialkylcarbonates.

Example 2 To 2.45 parts of pregnane-EOL,12/3Q21-tridl-20- one-21-monoacetate, prepared .as describedin Example 1, benzene is-added and the latter evaporated in vacuo at 50 C. so as to dry the prep aration. The product is now. boiled, excluding moisture, with 12.4 parts of aluminium-phenolate (freshly recrystallizedfrom a mixture of'benzene and petroleum ether), 500 parts 'of dry benzene and 170 parts of dry 'acetone'for 20hoursunder reflux on a boiling water-bath. After cooling; the mixture is evaporated down in vacuo,the'- residue extracted with plenty of ether, the'ether' solution washed with a -concentrated"solution 'of sodium potassium tartrate, with dilute hydrochlori'c acid, potassium bicarbonate solution and water, dried over sodium sulphate and evaporated down. The free phenolis then 'first fremovedas far as possible by heating in ahi'gh at 95 C. The crystalline residue, whichstill "contains some phenol; is dissolved in 120p'arts of dry benzene, diluted with the 'same 'quantityoi petroleum ether "and chromatographed "by "a'llowingto' run through a column of aluminiumoxid'e prepared with petroleum ether.

The extracts obtained with mixtures 'o'fbe'nzene and petroleum ether, benzene, and"benzene and" ether give oily products or ones which no not melt sharply. The extracts obtained with benzene and ether, ether, and ether and chloroformgive on evaporating down and recrystall'i'zing from benzene, 'pregnane-12 8;21'-diol3,20 dione zl monoacetate as colourless crystals, 'MJCPt. 190-1'92 C., [al =-|-'146j3i3 (in acetone). With chloroform and a mixture of chloroform, ethyl acetate and methyl alcoholga yellow amorphous product is eluted, which can be oxidized with chromic acid as maybe the pure product, to pregnane 21 ol 312,20 trione acetate (see Example 1).

4 parts of 'pregnane-IZBB1-diol-3;20rd'lone-21- monoacetate are dissolved in '60"p'arIts of pure. glacial acetic acid and brominated with anormal' solution of bromine in glacial acetic acid as described in Example 1. The mixture is then immediately evaporated down in. vacuo at 25 'C. and a little absolute ether added to the residue, when crystallization occurs. The crystals,a'fter. washing with some ether and a mixture of ether and petroleum ether melt at '1'71.172' C; with decomposition. The crystallizedbrom'ide is well dried and boiled under reflux with 50 parts of absolute pyridine for 5' hours. The mixture is then evaporated down in 'vacuo, the residue vdissolved in ether, the ether solution washed until neutral, dried and evaporated down. The crude crystalline aggregate is recrystallized once from a mixture of acetone and ether, then dissolved in benzene .and purified chromatographically over a column of'aluminium' oxide. The extracts thus obtained with benzene andether, absolute ether, and ether and chloroform (up to 1:4) crystallize from a mixture of acetone and ether in needles which melt, after washing-with ether, at 182-184 (in acetone). The substance is A pregnene-l2fi,.- 21-diol-3,20-dione-'2l mon'oacetate. The, substance shows in the ultraviolet absorption spectrum a bandwith amaximumat 244 mb, of which log 6:412 (in absolute alcohol).

In quite an analogous wayanother 2l--ester, vfor example the .propi'onate, butyrat'es', pa-imitate orvbenzoate, .is; obtained, when the synthesis started: with the corresponding ester;

'6 parts of the :said 2lmonoacetate are dissolved in fio'pa-rtsof methyl alcohol, a solution of 6 parts of potassium bicarbonate in 20 parts of: water isadded, and the whole allowed tostand for 15 :hours'atroom.temperature. Some more water. is thenaadded and the methyl alcohol removed completely in vacuo. The precipitated oily product is dissolved in ether, the ether solution washed several times with'a little water, dried and considerably concentrated down, when crystallization occurs. Double pyramids are obtained by recrystallization from av mixture of acetone and ether; they .rneltat 98 -'124 C. The specific rotation is I A stereo'isom'etic product can be obtained by using.

as starting' mater'ial for the synthesis the corresponding substanceisomeric in 12-position.

Example 3 5.8 parts of crude 21-diazo-pregnane-'3u,'12fidiol-20-one-diacetaite, prepared as described in Example. .1 from 4.7 parts of etio-de'soxycholi'c acid diacetate, are mixed with a solution of 2.8 parts potassium. carbonate and 0.7 part potassium bicarbonate in 51 parts of Water and parts of methyl alcohoLin order to saponify one of the two acetate groups, and the whole allowed to stand at room temperature for 44 hours. Water is added to the mixture which then is freed from methyl alcohol in vacuo and extracted with plenty of ether, when flocculent impurities remainundissolved. The ether solution is washed with Watendr'ied over sodium sulphate and evapora'teddown. Theibrown amorphous residue consis'ts mainlyof '21blaze-pregnanc 3a,12,B-diol-20- one-12-monoacetate.

The latter 'isheate'd to 105 C. with '22 parts of pure anhydrous glacial acetic acid. After 30 minutes approximately the calculated amount of nitrogen has been liberated and. the reaction is finished. The light brown solution is evaporated down to dryness in vacuo, the residue dissolved in 100 .parts of benzene, diluted with 300 parts of petroleum ether and chromatographed through a column .of. aluminium oxide. On elution with a mixture of benzene and ether crystals are obtained which, onrecrystallization .from a mixture of acetone andether,meltat 156-158 C. and havea specific rotation of [.a] =+150.7i2 (in acetone). They consist of pregnane-3a,12p,21- trio]-20-one-12,2bdiacetate. From further extractions with:chlor oform, a s-malliquantity of the 2 l-monoacetate described in Example 1 is also obtained.

2 parts of-the-diacetate "are dissolved in 22 parts of. pure glacial acetic acid, 23 parts of a 2 per cent solution-of chromium trioxide in glacial aceticacid are added and the whole allowed to stand for 16 hours at 20 C. The mixture is evaporated down in.-vacuo almost to dryness (t'emperature'of the bath 25:'C.-), water added to the residue, and the mixture extracted with'plen-ty of ether. "The ether solution iswasheduntil neutral, dried'and considerably concentrated. By the addition of petroleum ether, 1:4 partsof long, colourless rods are obtained which, on recrystallization from a mixture of ether and petroleum-ether, melt at '--1-22FC.. and have a specific rotation of alb "=+'1'42 ';4;-E4' (in-chloroform). They consist of pregnanc-125,21-diol-3,20 dione-diacetate.

The same product can also be obtained by the acetylation of pregnanc-l2,s,2l-diol-3,20-dione- 21-monoacetate (see Example 2).

Instead of first acetalyzing and then oxidizing the 21-diazo-pregnane-3m,l2p-diol 20 one-12- monoacetate, this compound may firstbe dehydrogenated to 2l-diazo-pregnane-3,20-dione-12 8- ol-acetate, for example by means of an aluminium alcoholate or phenolate in presence of acetone or cyclohexanone, and the latter then be acetolyzed to the pregnanc-1213,21-diol-3,20-dione diacetate.

2 parts of the diacetate are dissolved in 14 parts of pure glacial acetic acid and b-rominated with a normal solution of bromine in glacial acetic acid, as described in Example 1. The mixture is then immediately evaporated down in vacuo at 30 C. On the addition of absolute ether, the residue crystallizes and melts, after washing with ether "and a mixture of ether and benzine, at 165-1'76 C. with decomposition. The crystalline bromide is heated to boiling with 18 parts of pure pyridine for 5 hours under reflux. The solution is then evaporated down in vacuo, the residue dissolved in ether, the ether solution washed with hydrochloric acid, sodium carbonate solution and water, dried and evaporated down. The crystalline residue is recrystallized once from acetone-ether, the crystals, which do not melt sharply, dissolved in 20 parts of benzene, the solution diluted with '80 parts of petroleum ether and chromatographed by allowing to run through a column of aluminium oxide. From the fractions eluted with absolute benzene, and benzene ether, colourless, glossy, double pyramids'M. Pt. 158-159 C., are obtained by recrystallization from a mixture of acetone, ether and hexane. The specific rotation is [a] =+197.7i5 (in acetone).

The substance shows in the ultraviolet absorption spectrum a band with a maximum at 244 mp and log 6 4.15 (in alcohol) and thus consists of M-pregnene-12p,21-diol-3,20 -dione diacetate. The same product can be obtained by acetylation of A' pregnene-l2 3,21-dio1-3,20-dione (see Example 2) with acetic anhydride and absolute pyridine for 1. hour at 95 C.

'7 parts of the diacetate are dissolved in 550 parts of methyl alcohol, a solution of 12 parts of potassium bicarbonate in' 300 parts of water is added, and the whole allowed to stand for 1'? hours at 20 C. Some Water is then added, the

methyl alcohol removed in vacuo and the amorphous residue dissolved in a mixture of ether and chloroform (9:1). The ether and chloroform solution is washed several times with a little Water, dried over sodium sulphate and evaporated down. The residue, after recrystallization from a mixture of benzene and ether, and from acetone and ether, gives colourless octahedrons,

which melt at 188-192 C. and have a specific rotation of [a] 185.3 22; [0t]5464 :+226.3i3 (in acetone). They consist of M-pregnene-12e,21-diol-3,20-dione 12- monoacetate.

Example 4 sodium sulphate and evaporated down.

reflux for 4 hours with a solution of 2 parts of potassium hydroxide in 2 parts of water and 20 parts of methyl alcohol. After the addition of 10 parts of water, the methyl alcohol is removed in vacuo, hydrochloric acid added to the residue, cooling continually, until acid reaction to congo is reached, and the precipitated crystalline acid filtered oil by suction, washed with water and dried in vacuo. The product melts indefinitely and consists of a mixture of the stereo-isomeric 3aand 35,11-dihydroxy-etiocholanic acids. It is partially acetylated by boiling under reflux for one hour with 5 parts of glacial acetic acid and 1 part of acetic anhydride; 2 parts of water are then added, a drop at a time, while the mixture is still hot, and boiling is continued for another 15 minutes. After the addition of more water, the mixture is considerably concentrated in vacuo and the acid completely precipitated by a further addition of water, filtered oil by suction and dried in vacuo. The yellow crystalline substance has the formula CzzHnOs and melts indefinitely, as it consists of a mixture of the stereo-isomeric 30:- and 3cacetoxy-ll-hydroxy-etio-cholanic acids. The yield is 1.1 parts. The well-dried product is dissolved in 6 parts of pure thionyl chloride and allowed to stand for 16 hours at room temperature, excluding moisture. The solution is then evaporated down in vacuum and the residue, crude A -3-acetoxy-etio-cholenic acid-chloride, dissolved in 10 parts of dry benzene.

The benzene solution of the parent material thus obtained is introduced at 0 C. into a dry ether solution of diazomethane prepared from 5 parts of nitrosomethyl carbamide. This mixture is first allowed to stand for 2 hours at 0 C., then for 12 hours at room temperature, is then evaporated down at a bath temperature of 50 C. and the residue dried in vacuo. The obtained 1.15 parts of crude yellow diazoketone are dissolved in 15 parts of methyl alcohol, a solution of 0.75 part potassium hydroxide in 1 part of water and 35 parts of methyl alcohol is added,

" and the whole allowed to stand for 8 hours at with 200 parts of dry benzene, parts of dry acetone and 5 parts of aluminium phenolate. It is then concentrated down considerably, the residue extracted with ether and the ether solution washed with very dilute hydrochloric acid, sodium carbonate solution and water, dried over The residue is very well evacuated until the free phenol has been completely removed. This crude product is heated for 30 minutes to C. with 15 parts of pure anhydrous glacial acetic acid, when nitrogen escapes freely. Evaporation in vacuo gives crude 5 21-aoet0xypregnene-3,20- dione. It is purified chromatographically by allowing a solution of it to run through A1203. The diketone is removed from the column with absolute benzene and can be obtained in a pure condition by recrystallization from a mixture of ether and petroleum ether. A product which does not melt quite sharply at is suitable, however, for working up. The colourless crystals have an empirical formula of 0231-13504; they rapidly reduce alkaline silver-diammine solution M'Zacce .11 :at room temperature and give, when dissolved in a little chloroform, a pronounced yellow colour with tetra-nitro-methane.

Instead of dehydrogenating the 3-hydroxydiazoketone, the latter may be acetolyzed to the ZLacetQXy-ketone and then be oxidized, for ex ample With chromium trioxide in glacial acetic acid, the nuclear double bond being protected before the oxidation, e. g. by addition of bromine, and regenerated afterwards, for example by reacting with zinc dust or an alkali iodide.

ihe product is now brominated in glacial acetic acid with 2 mols bromine and then debrominated by boiling for hours with absolute pyridine or by heating to 150 C. for 2 hours with dimethylaniline. The crude product is heated to 80 C. for 15 minutes with 0.5 part of zinc dust and parts of glacial acetic acid, rotating continually. 'After filtration it is evaporated down in vacuo, extracted with ether, the solution washed with dilute hydrochloric acid, sodium carbonate solution and water, dried over sodium sulphate and evaporated down. The residue is purified chromatographically. From the fractions eluted with benzene, and with benzene and ether (99:1), colourless thin prisms are obtained, on recrystallization from ether, which melt at 158-159 C. and have a specific rotation of [a] =|l29 C. (acetone). The substance has the empirical formula C23H30O4, reduces alkaline silver-diammine solution rapidly and markedly at room temperature; dissolved in a little chloroform, it gives a pronounced yellow colour on the addition of tetranitromethane. The product, A -21-acetoxy pregnadiene 3,20- dione, is distinguished by a very high activity on adrenal-ectomized rats.

Starting from A J -3aor A -3p-acetoxyetio-cholenic acid, M -2l-acetoxy-pregnadiene-'3,20-dione, melting at 141 C. and crystallizing from ether in fine needles, can be obtained in a similar way. It shows a specific rotation [a] =+93 (in acetone).

Example 5 23 parts of 3l3-acetoxy-ll-keto-etio-cholanic acid, M. Pt. 110-112 C. (obtainable as described in U. S. Patent application Serial No. 474,726; Pat. No. 2,403,683, granted July 9, 1946, are dissolved at 0 C. in 140 parts of very pure thionyl chloride, and allowed to stand, with exclusion of moisture, at first for 30 minutes at 0 C., andthen for 16 hours at 18 C. The solution is then concentrated down in vacuo (temperature of the bath 40 C.), the residue dissolved in 500 parts of dry benzene and the solution added at 0 C. to a freshly distilled solution of diazomethane in ether which has been prepared from 100 parts of nitroso-methyl carbamide and dried over potassium hydroxide; gas is immediately liberated. The mixture is allowed to stand, at first for 2 hours at 0 C., with exclusion of. moisture, and then for 16 hours at 18 0.; it is then concentrated down considerably at a bath temperature of 50 C., and finally completely dried in vacuo. The residue weighs 25 parts.

The crude 21 diazopregnane 3p o1 11,20 dione-acetate is dissolved in 300 parts of methyl alcohol, a solution of 15 parts of potassium hydroxide in parts of Water and 700 parts of methyl alcohol added, and the whole allowed to stand for 8 hours at 20 C. A solution of 32 parts of potassium bicarbonate in. 1000 parts of water is then added, the methyl alcohol removed in vacuo I and the remaining suspension extracted 'witha chloride.

12 largequantity of. ether. The ether solution, after washing with water and drying over sodium sulphate, is concentrated at a bath temperature of 50 C. and then completely evaporated down in vacuo, 24 parts of crude 21-diazo-pregnane-3flol -11,20-dione remaining as a light brown resin.

The latteris then heated for 30 minutes to -100" C. with 300 parts of pure anhydrous glacial acetic acid and the nitrogen liberated collected over water in a measuring cylinder. Whenthe liberation of nitrogen is complete, the solution is evaporated down in vacuo. The 24 parts of residue which remain are purified in the known way chromatographically over aluminium oxide- The; extracts obtained with mixtures of benzone; and ether. give, on recrystallization from other and petroleum ether pregnane-3;3,2l-diol- 11,20-.dionee21-monoacetate in colourless platelets melting, at 178-181 C. Acetylation with acetic anhydride and pyridine gives thecorresponding, diacetate, M. Pt. 169-171 C.

8.5 parts ofv the monoacetate described are dissolved in parts of glacial acetic acid, 100 parts of a 2%- solution of. chromium trioxide in glacial acetic acid 2 parts CrO3) added, and the whole is allowed to standofor. 16 hours at 20 C. It is then concentrated down in vacuo at a, bath temperature of 30 C., water added and the Whole extracted with ether. The ether solution is washed with dilute sulphuric acid, sodium carbonate solution. and water, dried over sodium sulphate and concentrated. Crystallization, which soon sets in, is. completed by the addition of some petroleum ether. In this way ,pregnane-3,11,20-trione-21- ol-acetate is. obtained. in colourless needles, M. Pt. 153-155? C., which show a specific rotation (concentration 0.783 in acetone).

Instead. of first acetolyzing and then oxidizing the 21. diazo pregnane-lifi-ol-11,20-dione, this compound may first be dehydrogenated to 21- diazo-pregnane-3,11,20-trione, for example by means of an. aluminium alcoholate or phenolate in presence of acetoneor cyclohexanone, and the latter then be acetolyzed. to the 21-acetoxypregna-ne-3,11,20-trione.

Instead of adding. the BB-acetoxy-ll-keto-etio- .cholanic acid-chloride to an excess of diazomethane. solution, the latter solution may be added slowly to. the benzene solution of the said acid- In. this case the corresponding 21- chloro-ZO-ketone is. obtained, which after saponificationand oxidation of the substituent in 3- position, for example by means of alcoholic hydrochloric acid and of chromic acid, can be converted also to. the pregnane-3,11,20-trione-2lol-acetate by means, for example, of. an alkali acetate in acetone or glacial acetic acid or of silver acetate.

A normal bromine solution is first prepared by mixing 10 parts of bromine with 384 parts of glacial acetic acid. 9.6 parts of the pregnanc- 3,11,20-tri0ne-21-ol-acetate are dissolved in 50 parts of glacial acetic acid and 2 drops of the above solution then added. After a few minutes -'dec0lo11rizati0n suddenly occurs, after which a further 48 parts of the bromine solution are added, cooling and rotating, and are almost immedia-tel-y decolourized. Crystallization occurs after evaporating down in vacuo at a bath temperature. of 25 C. The colourless crystals, after washing. with ether, melt at -185 C. They consist of 4-bromo-pregnane-3J1,20-trione-21- ol-acetate.

This bromide is boiled under reflux for hours with 100 parts of absolute pyridine. After evaporating down in vacuo, the residue is dissolved in a large quantity of ether, the ether solution washed with a little dilute hydrochloric acid, sodium carbonate solution and water, dried over sodium sulphate and evaporated down. The residue is purified chromatographically over a column of aluminium oxide, when the first benzene extracts given crystals which melt indefinitely at a low temperature. The further benzene, and benzene and ether fractions give, after recrystaliizing twice from a mixture of acetone and ether, colourless needles melting at 175-178 C. and having a specific rotation [a] =+2l0.7- .-3 (concentration 0.676 in acetone). They consist of A -pregnene-3,11,20-trione-21 ol-acetate (dehydro-corticosterone-acetate). A sample of very pure natural dehydro corticosterone acetate melts, under the same conditions, at 177-179 0.,

has the above specific rotation and a mixture with the synthetic product gives no melting point depression. Saponification with methyl alcoholic I-ICl or potassium bicarbonate in aqueous methyl alcohol gives the free dehydro-corticosteroneacetate, melting at 174-180 C.

Instead of the 3B-acetoxy-1l-keto-etio-cholanic acid an ester stereoisomeric in 3-position can be used as starting product. If the process is started, however, from a 3,11-diacyloxy-etiocholanic acid (if desired with different ester groups in 3- and ll-position) corticosterone, 11- iso-corticosterone, or their ll-mono-esters or 11,21-diesters may be obtained in an analogous way, whereby the possibility exists of preparing mixed diesters. The intermediate products in the latter syntheses are for example the pregnane--ones, containing in ll-position a hydroxyl group or a group convertible into hydroxyl by hydrolysis, in 3-positi0n the said groups or a keto group and in 21-position a halogen or a diazo group.

This application is a division of my application Serial No. 474,892, filed February 5, 1943, now Patent No. 2,401,775, dated June 11, 1946.

What I claim is:

1. A process for the manufacture of an a-Sllbstituted side-chain ketone of the cyclopentanopolyhydrophenanthrene series, which comprises reacting with an aliphatic diazo compound a carboxylic acid halide of the aforesaid series which contains in ring A in 3-position a group convertible into hydroxyl by hydrolysis and in ring C a double bond in one of the positions 9, 11 and 11, 12, subjecting the resultant diazoketone to the action of a hydrolyzing agent whereby the group present in 3-position is converted into free hydroxyl, reacting the resultant product with a dehydrogenating agent whereby the free hydroxyl in 3-position is converted into keto and then with an acid whereby the diazoketo radical is converted into an esterified ketol radical.

2. A process for the manufacture of an a-Sllbstituted side-chain ketone of the cyclopentanopolyhydrophenanthrene series, which comprises reacting with an aliphatic diazo compound a carboxylic acid halide of the aforesaid series which contains in ring A in 3-position a group convertible into hydroxyl by hydrolysis and in ring C a double bond in one of the positions 9, 11 and 11,

12, subjecting the resultant diazoketone to the action of a hydrolyzing agent whereby the group present in 3-position is converted into free hydroxyl, reacting the resultant product with an acid whereby the diazoketo radical is converted into an esterified ketol radical and then with a dehydrogenating agent whereby the free hydroxyl in 3-position is converted into keto,

3. A process for the manufacture of an a-substituted side-chain ketone of the cyclopentanopolyhydrophenanthrene series, which comprises reacting with an aliphatic diazo compound a carboxylic acid halide of the aforesaid series which contains in ring A in 3-position a group convertible into hydroxyl by hydrolysis and no double bond in a-position to the said group and in ring C a double bond in one of the positions 9, 11 and 11, 12, subjecting the resultant diazoketone to the action of a hydrolyzing agent whereby the group present in 3-position is converted into free hydroxyl, reacting the product with an acid whereby the diazoketo radical is converted into an esterified ketol radical, then with a dehydrogenating agent whereby the free hydroxyl in 3- position is converted into keto, and finally introducing a double bond into the a-position to the S-keto group by reaction with a halogenating agent followed by reaction with a reagent for eliminating hydrogen halide.

4. A process for the manufacture of an a-substituted side-chain ketone of the cyclopentanopolyhydrophenanthrene series, which comprises reacting with an aliphatic diazo compound a carboxylic acid halide of the aforesaid series which contains in ring A in 3-position a group convertible into hydroxyl by hydrolysis and no double bond in iii-position to the said group and in ring C a double bond in one of the positions 9, 11 and 11, 12, subjecting the resultant diazoketone to the action of a mild hydrolyzing agent whereby only the group present in 3-position is selectively converted into free hydroxyl, reacting the product with an acid whereby the diazoketo radical is converted into an esterified ketol radical, then with a dehydrogenating agent whereby the free hydroxyl in 3-position is converted into keto, and finally introducing a double bond into the e-position to the 3-keto group by reaction with a halogenating agent followed by reaction with a reagent for eliminating hydrogen halide.

5. A A -21-acetoxy-pregnadiene 3,20 dione containing a double bond in one of the positions 9,11 and 11,12.

6. The A -21 acetoxy pregnadiene-3,20- dione.

7. The A -21 acetoxy-pregnadiene-3,20- dione.

TADEUS REICHSTEIN.

REFERENCES CITED The following references are of record in the V file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Eistert, Berichte, 69, 1074-1079 (1936). 

